1. Field of the Invention
The present invention relates to a technical field on such a fail-safe or fail-soft as a failure countermeasure control apparatus and method for a hybrid vehicular drive system, the hybrid vehicular drive system having an engine and two motors/generators (motors functioning as generators and vice versa) as power sources (or drive sources).
2. Description of the Related Art
A Japanese Patent Application First Publication No. 2000-102106 published on Apr. 7, 2003 exemplifies a previously proposed hybrid vehicle. In the previously proposed hybrid vehicle in the above-described Japanese Patent Application First Publication, the engine, two planetary gear sets, and the two motor/generators which control sun gears of the two planetary gear sets, a carrier of one of the two planetary gear sets being coupled to the engine, and a ring gear of one of the two planetary gear sets being coupled to the road wheels.